Duration of Protection of Nirsevimab Against Hospitalisation for Respiratory Syncytial Virus Infection

May 19, 2025 updated by: Asmaa El-Heneidy, Griffith University

Queensland Infant Birth Dose RSV Immunisation Program 2024 - Duration of Protection and Impact

Respiratory syncytial virus (RSV) is a leading cause of hospitalizations for acute lower respiratory tract infection (LRTI) in infants. In Australia approximately 1.5% of infants are hospitalized due to RSV, 80% of whom are born full-term and are otherwise healthy. Two randomized trials have used a seasonal implementation strategy to show nirsevimab, a long-acting monoclonal antibody, has sustained efficacy against RSV LRTI hospitalizations in the first 150-180 days after administration. Nirsevimab has been approved in many countries for the prevention of RSV-LRTI in neonates and infants. However, the protection offered by nirsevimab beyond 180 days remains unknown. Queensland is a large Australian state spanning the tropical and sub-tropical climate zones, where RSV circulates year-round. The Queensland government publicly funded nirsevimab for all infants at birth from 15 April 2024. The aim of this study is to estimate the duration of effectiveness of nirsevimab against RSV-related hospitalizations.

A case-control study will be conducted using routinely collected linked data. Cases will be children born in Queensland from 15 April 2024 to 14 April 2025 who are hospitalised with an RSV-related condition prior to 14 April 2026. Controls will be drawn from the set of infants who are admitted to the same hospital in a 5:1 ratio, and matched on age and sex using the Queensland Perinatal Data Collection. Nirsevimab receipt will be extracted from hospital's electronic medical records and linked to hospitalization data by the Queensland Health Data Linkage Unit. Duration of protection against RSV-related hospitalisation due to nirsevimab will be assessed using multivariable logistic regression model accounting for matching and adjusting for confounding variables.

This case-control study will determine the level and duration of protection offered by nirsevimab in a region with year-round RSV circulation and inform future prevention strategies. Interim analysis is expected to be available at the time of the conference, allowing for early dissemination of this first evidence about nirsevimab duration of protection beyond 180 days.

Funding: From Sanofi and AstraZeneca through a collaboration grant.

Study Overview

Status

Active, not recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

4350

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Queensland
      • Gold Coast, Queensland, Australia, 4215
        • Griffith University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Our study population will consist of all infants born in Queensland between 15 April 2024 and 30 April 2025 and hospitaliszed for any reason between 15 April 2024 and 30 April 2026.

Cases will be All infants born in Queensland between 15 April 2024 and 30 April 2025 who were admitted to any hospital in Queensland (public and private) between 15 April 2024 and 30 April 2026 with a respiratory related principle or other diagnosis (ICD codes J21.0, J20.5, J12.1, B97.4). Controls will be defined as infants admitted to the same hospital that do not have a diagnosis of (ICD codes J21.0, J20.5, J12.1, B97.4) and that the admission is not an elective admission.

For each included case, five controls (where possible) matched on month of birth and sex will be requested to enable appropriate comparison.

Description

Inclusion Criteria: Any infant born between 15 April 2024 and 30 April 2025 and hospitalized for any reason between 15 April 2024 and 30 April 2026.

Exclusion Criteria: Infants who admitted to hospitals with an elective admission. ((i.e. admissions that are planned ahead of time, such as scheduled surgeries or other pre-arranged medical procedures).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
RSV hospitalised infant
Description: Cases (RSV hospitalised infant) will be children born in Queensland from 15 April 2024 to 14 April 2025 who are hospitalised with a RSV-related condition prior to 14 April 2026. Nirsevimab receipt will be extracted from hospital's electronic medical records and linked to hospitalisation data by the Queensland Health Data Linkage Unit.
Non-RSV hospitalised infant
Description: Controls (Non-RSV hospitalised infant) will be drawn from the set of infants who are admitted to the same hospital in a 5:1 ratio, and matched on age and sex using the Queensland Perinatal Data Collection. Nirsevimab receipt will be extracted from hospital's electronic medical records and linked to hospitalization data by the Queensland Health Data Linkage Unit.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
The duration of effectiveness of nirsevimab against RSV-related hospitalizations.
Time Frame: From mid April 2024 to mid April 2026
From mid April 2024 to mid April 2026

Secondary Outcome Measures

Outcome Measure
Time Frame
Estimate the quantities of the laboratory confirmed RSV hospitalization length of stay and paediatric intensive care unit admission that were prevented by a 12-month year-round nirsevimab immunization program in Queensland infants.
Time Frame: From mid April 2024 to mid April 2026
From mid April 2024 to mid April 2026
Estimate the quantities of all cause acute respiratory hospitalization and PICU admissions that were prevented by nirsevimab immunization program in Queensland infants
Time Frame: From mid April 2024 to mid April 2026
From mid April 2024 to mid April 2026
Estimate the quantities of all death from RSV-related illness that were prevented by a 12-month year-round nirsevimab immunization program in Queensland infants
Time Frame: From mid April 2024 to mid April 2026
From mid April 2024 to mid April 2026
Evaluate the impact of nirsevimab on the cost of hospital services in Queensland, Australia
Time Frame: From mid April 2024 to mid April 2026
From mid April 2024 to mid April 2026

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 15, 2024

Primary Completion (Estimated)

April 15, 2026

Study Completion (Estimated)

March 31, 2027

Study Registration Dates

First Submitted

May 19, 2025

First Submitted That Met QC Criteria

May 19, 2025

First Posted (Actual)

May 29, 2025

Study Record Updates

Last Update Posted (Actual)

May 29, 2025

Last Update Submitted That Met QC Criteria

May 19, 2025

Last Verified

February 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2024/851
  • VAS00012 (Other Grant/Funding Number: Sanofi Pasteur S.A)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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